<!--********************************************************************
* by jiawanlong
*********************************************************************-->
<!DOCTYPE html>
<html>

<head>
    <meta charset="UTF-8" />
    <link rel="stylesheet" href="./../../cesium/Cesium1.98/Widgets/widgets.css">
    <script type="text/javascript" src="./../../cesium/Cesium1.98/Cesium.js"></script>
</head>

<body style="margin: 0; overflow: hidden; background: #fff; width: 100%; height: 100%; position: absolute; top: 0">
    <div id="map" style="margin: 0 auto; width: 100%; height: 100%"></div>
    <script type="text/javascript">

        Cesium.Ion.defaultAccessToken = 'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJqdGkiOiI3ZjQ5ZGUzNC1jNWYwLTQ1ZTMtYmNjYS05YTY4ZTVmN2I2MDkiLCJpZCI6MTE3MTM4LCJpYXQiOjE2NzY0NDUyODB9.ZaNSBIfc1sGLhQd_xqhiSsc0yr8oS0wt1hAo9gbke6M'
        const viewer = new Cesium.Viewer('map', {});
        viewer.imageryLayers.remove(viewer.imageryLayers.get(0));

        // ImageryLayer
        // ImageryLayerCollection
        // ImageryProvider
        // ImageryProvider子类

        // https://cesium.com/learn/cesiumjs/ref-doc/ImageryLayer.html#.ConstructorOptions

        var imageryProvider = new Cesium.SingleTileImageryProvider({
            "url": "./world_b.jpg",
        })

        let options = {
            alpha: 0.9,
            hue: 0.3,
            saturation: 0.3,
            gamma: 0.3,
        }

        var imageryLayer = new Cesium.ImageryLayer(imageryProvider, options);
        viewer.imageryLayers.add(imageryLayer)

        imageryLayer.alpha = 0.5
    </script>
</body>

</html>